Individual having a parent with early-onset gastric cancer may need screening at younger age

Differences in Ancestry and Presence of Gastric Precursor Lesions in Individuals With Young- and Average-Onset Gastric Cancer

BACKGROUND

There has been a paradoxical rise in young-onset gastric cancer (YOGC), defined as gastric cancer (GC) diagnosed before age 50. Precursor lesions may contribute to pathogenesis, though their role in progression to different histologic subtypes is unclear. The impact of self-reported race is also poorly characterized and may be unreliable as a proxy for genetic differences. We aimed to compare differences in histology and genetic ancestry between YOGC and average-onset gastric cancer (AOGC).

METHODS

This retrospective cohort included all patients with GC at Memorial Sloan Kettering (MSK) from January 2013 to March 2021. Data on demographics, tumor characteristics, and precursor lesions were collected. Genetic ancestry was inferred from MSK-Integrated Mutation Profiling of Actionable Cancer Targets panel.

RESULTS

Of 1685 individuals with GC, 290 had YOGC. Compared to AOGC, individuals with YOGC tended to be female, Hispanic, foreign-born, and feature diffuse-type histology. YOGC was less likely to have precursor lesions, including intestinal metaplasia (20% vs. 37%, p < 0.01) and dysplasia (4% vs. 14%, p < 0.01). Of 560 patients with ancestry data, 127 had YOGC. Admixed, East Asian, and South Asian ancestries were more likely to present with YOGC while Europeans presented with AOGC. Intestinal metaplasia was enriched among East Asians, maintained when stratifying by histology and GC onset.

CONCLUSIONS

We observed YOGC was more common in East and South Asians, and while YOGC may be less likely to develop in the setting of precursor lesions these high-risk states may also be enriched in East Asians. Future research is needed to understand drivers behind such differences and outcome disparities given these individuals may be less amenable to endoscopic interventions.

The microbiome and rise of early-onset cancers: knowledge gaps and research opportunities

Accumulating evidence indicates an alarming increase in the incidence of early-onset cancers, which are diagnosed among adults under 50 years of age, in the colorectum, esophagus, extrahepatic bile duct, gallbladder, liver, stomach, pancreas, as well as the bone marrow (multiple myeloma), breast, head and neck, kidney, prostate, thyroid, and uterine corpus (endometrium). While the early-onset cancer studies have encompassed research on the wide variety of organs, this article focuses on research on digestive system cancers. While a minority of early-onset cancers in the digestive system are associated with cancer-predisposing high penetrance germline genetic variants, the majority of those cancers are sporadic and multifactorial. Although potential etiological roles of diets, lifestyle, environment, and the microbiome from early life to adulthood (i.e. in one's life course) have been hypothesized, exact contribution of each of these factors remains uncertain. Diets, lifestyle patterns, and environmental exposures have been shown to alter the oral and intestinal microbiome. To address the rising trend of early-onset cancers, transdisciplinary research approaches including lifecourse epidemiology and molecular pathological epidemiology frameworks, nutritional and environmental sciences, multi-omics technologies, etc. are needed. We review current evidence and discuss emerging research opportunities, which can improve our understanding of their etiologies and help us design better strategies for prevention and treatment to reduce the cancer burden in populations.

Helicobacter pylori-activated fibroblasts as a silent partner in gastric cancer development

The discovery of Helicobacter pylori (Hp) infection of gastric mucosa leading to active chronic gastritis, gastroduodenal ulcers, and MALT lymphoma laid the groundwork for understanding of the general relationship between chronic infection, inflammation, and cancer. Nevertheless, this sequence of events is still far from full understanding with new players and mediators being constantly identified. Originally, the Hp virulence factors affecting mainly gastric epithelium were proposed to contribute considerably to gastric inflammation, ulceration, and cancer. Furthermore, it has been shown that Hp possesses the ability to penetrate the mucus layer and directly interact with stroma components including fibroblasts and myofibroblasts. These cells, which are the source of biophysical and biochemical signals providing the proper balance between cell proliferation and differentiation within gastric epithelial stem cell compartment, when exposed to Hp, can convert into cancer-associated fibroblast (CAF) phenotype. The crosstalk between fibroblasts and myofibroblasts with gastric epithelial cells including stem/progenitor cell niche involves several pathways mediated by non-coding RNAs, Wnt, BMP, TGF-β, and Notch signaling ligands. The current review concentrates on the consequences of Hp-induced increase in gastric fibroblast and myofibroblast number, and their activation towards CAFs with the emphasis to the altered communication between mesenchymal and epithelial cell compartment, which may lead to inflammation, epithelial stem cell overproliferation, disturbed differentiation, and gradual gastric cancer development. Thus, Hp-activated fibroblasts may constitute the target for anti-cancer treatment and, importantly, for the pharmacotherapies diminishing their activation particularly at the early stages of Hp infection.

Comparison of survival between diffuse type and intestinal type early-onset gastric cancer patients: A large population-based study

Currently, little knowledge about the survival of early-onset gastric cancer and little evidence about the difference of survival based on Lauren type has been reported. In order to investigate the difference, we conducted a retrospective study using the Surveillance, Epidemiology, and End Results (SEER) database and compared it comprehensively. SEER database was used to extracted patients and multiple imputation was utilized to fill blank data. Multivariate cox regression analysis and competing risk model were used to identify the risk factors of survival. K-M survival curve and propensity score matching (PSM) was applied to compare the difference of survival of patients based on Lauren type. Totally, we extracted 3932 EOGC patients including 2086 diffused type and 1846 intestinal type. K-M survival curve showed patients aged 20 to 29 had worse survival compared to patients aged at 30 to 45 years. The survival of EOGC patients would be greatly improved after surgery. Multivariate cox regression analysis revealed diffused type was an independent risk factor, as well as T stage, lymph node metastasis, tumor size (>5 cm) and metastasis, while surgery treatment and examined lymph nodes were protective factors. Multivariate competing risk regression model also showed diffused type was risk factor. We performed PSM by matching 1433 diffused EOGC with 1433 intestinal EOGC patients, finding patients with diffused type had a poorer survival. our results revealed that compared to diffused type EOGC, intestinal type was characterized by a better survival. EOGC should be attached more attention by clinicians.

Is early-onset cancer an emerging global epidemic? Current evidence and future implications

Over the past several decades, the incidence of early-onset cancers, often defined as cancers diagnosed in adults <50 years of age, in the breast, colorectum, endometrium, oesophagus, extrahepatic bile duct, gallbladder, head and neck, kidney, liver, bone marrow, pancreas, prostate, stomach and thyroid has increased in multiple countries. Increased use of screening programmes has contributed to this phenomenon to a certain extent, although a genuine increase in the incidence of early-onset forms of several cancer types also seems to have emerged. Evidence suggests an aetiological role of risk factor exposures in early life and young adulthood. Since the mid-20th century, substantial multigenerational changes in the exposome have occurred (including changes in diet, lifestyle, obesity, environment and the microbiome, all of which might interact with genomic and/or genetic susceptibilities). However, the effects of individual exposures remain largely unknown. To study early-life exposures and their implications for multiple cancer types will require prospective cohort studies with dedicated biobanking and data collection technologies. Raising awareness among both the public and health-care professionals will also be critical. In this Review, we describe changes in the incidence of early-onset cancers globally and suggest measures that are likely to reduce the burden of cancers and other chronic non-communicable diseases.

Severity of gastric intestinal metaplasia predicts the risk of gastric cancer: a prospective multicentre cohort study (GCEP)

OBJECTIVE

To investigate the incidence of gastric cancer (GC) attributed to gastric intestinal metaplasia (IM), and validate the Operative Link on Gastric Intestinal Metaplasia (OLGIM) for targeted endoscopic surveillance in regions with low-intermediate incidence of GC.

METHODS

A prospective, longitudinal and multicentre study was carried out in Singapore. The study participants comprised 2980 patients undergoing screening gastroscopy with standardised gastric mucosal sampling, from January 2004 and December 2010, with scheduled surveillance endoscopies at year 3 and 5. Participants were also matched against the National Registry of Diseases Office for missed diagnoses of early gastric neoplasia (EGN).

RESULTS

There were 21 participants diagnosed with EGN. IM was a significant risk factor for EGN (adjusted-HR 5.36; 95% CI 1.51 to 19.0; p<0.01). The age-adjusted EGN incidence rates for patients with and without IM were 133.9 and 12.5 per 100 000 person-years. Participants with OLGIM stages III-IV were at greatest risk (adjusted-HR 20.7; 95% CI 5.04 to 85.6; p<0.01). More than half of the EGNs (n=4/7) attributed to baseline OLGIM III-IV developed within 2 years (range: 12.7-44.8 months). Serum trefoil factor 3 distinguishes (Area Under the Receiver Operating Characteristics 0.749) patients with OLGIM III-IV if they are negative for H. pylori. Participants with OLGIM II were also at significant risk of EGN (adjusted-HR 7.34; 95% CI 1.60 to 33.7; p=0.02). A significant smoking history further increases the risk of EGN among patients with OLGIM stages II-IV.

CONCLUSIONS

We suggest a risk-stratified approach and recommend that high-risk patients (OLGIM III-IV) have endoscopic surveillance in 2 years, intermediate-risk patients (OLGIM II) in 5 years.

Screening and surveillance for gastric cancer: Does family history play an important role in shaping our strategy?

Family history is an important risk factor of gastric cancer. No guidelines have been developed that target gastric cancer with a family history; only hereditary familial gastric cancer is targeted. We review the available evidence regarding the familial aggregation mechanisms of gastric cancer and a strategy of screening and surveillance for gastric cancer in individuals with a positive family history of the disease. As there is a synergic effect of Helicobacter pylori infection and family history on the increased risk of gastric cancer, Helicobacter pylori eradication should be considered in all infected individuals with a family history of gastric cancer. Currently, there is weak evidence indicating that suitable timing to initiate eradication therapy is at the age of 20, when precancerous lesions, including significant gastric atrophy and intestinal metaplasia, have not been established. Reasonable timing to initiate screening for gastric cancer in individuals with a family history of gastric cancer is 10 years prior to the age of onset of gastric cancer in affected relatives. A 2-year surveillance interval, instead of the 3-year interval recommended in the present guidelines, may be better to detect early gastric cancer in those individuals who have already developed precancerous gastric lesions.

Prevalence of gastric cancer precursors in gastroscopy-screened adults by family history of gastric cancer and of cancers other than gastric

Background

People are at a high risk of gastric cancer if their first-degree relatives suffered from atrophic gastritis (AG), intestinal metaplasia (IM), intraepithelial neoplasia (IEN), dysplasia (DYS), or gastric cancer (GC). This study was performed to analyse the association between FDR-GC and GC precursors.

Methods

A cross-sectional study was performed to screen the prevalence of GC precursors from November 2016 to September 2019. A total of 1329 participants with FDR-GC, 193 participants with a family history of non-gastric cancer in FDRs (FDR-nGC), and 860 participants without a family history of cancer in FDRs (FDR-nC) were recruited in this study. The logistic regression model was used in this study.

Results

The prevalence of normal, Non-AG, AG/IM, IEN/DYS, and GC was 31.91, 44.21, 13.81, 8.73, and 1.34%, respectively. The prevalence of IEN/DYS was higher in people with FDR-GC and FDR-nGC (FDR-GC: odds ratio (OR) = 1.655; 95%CI, 1.153–2.376; FDR-nGC: OR = 1.984; 95%CI, 1.122–3.506) than those with FDR-nC. The younger the age at which FDRs were diagnosed with GC, the more likely the participants were to develop AG/IM (P_trend = 0.019). The risk of precursors to GC was higher in participants whose FDR-GC was the mother than in those whose FDR-GC was the father or sibling (OR, non-AG: 1.312 vs. 1.007, 1.274; AG/IM: 1.430 vs. 1.296, 1.378; IEN/DYS: 1.988 vs. 1.573, 1.542). There was no statistically significant difference in non-AG (OR = 1.700; 95%CI, 0.940–3.074), AG/IM (OR = 1.291; 95%CI, 0.579–2.877), and IEN/DYS (OR = 1.265; 95%CI, 0.517–3.096) between participants with one or more FDR-GC.

Conclusion

People with FDR-GC and FDR-nGC are at a high risk of IEN/DYS. When an FDR was diagnosed at a younger age, the risk of AG/IM was higher. The risk of GC precursors was higher in people whose FDR-GC was the mother.

Disparate and Alarming Impact of Gastrointestinal Cancers in Young Adult Patients

BACKGROUND

The rise in the incidence of gastric cancer (GC) and colorectal cancer (CRC) in young adults (YA) remains unexplained. We aim to identify differences in these malignancies between YA and older patients.

PATIENTS AND METHODS

We retrospectively analyzed the California Cancer Registry for all GC and CRC cases from 2000 to 2012. Pearson's Chi square analysis and stepwise regression model with backward elimination were used to analyze differences in demographic, clinical, and histopathologic features, and log-rank test to compare survival between young (≤ 40 years) and older adults (41-90 years) with GC or CRC, separately.

RESULTS

We analyzed 19,368 cases of GC and 117,415 cases of CRC. YA accounted for 4.6% of GC (n = 883) and 2.8% of CRC (n = 3273) patients. Compared with older patients, YA were more likely to be Hispanic (P < 0.0001) and have poorly differentiated (P < 0.0001), higher histologic grade (P < 0.0001), and signet ring features (P < 0.0001). Synchronous peritoneal metastases were more common in YA patients (32.1% vs. 14.1% GC, 8.8% vs. 5.4% CRC, P < 0.0001). The 5-year overall survival (OS) of YA with CRC or GC was longer than that of older patients with the same stage of malignancy; except YA with stage I GC, who demonstrated poor OS and disease-specific survival (DSS) (65.1% and 67.9%, respectively) which were significantly worse than those of adults aged 41-49 years (70.7% and 76.2%, respectively) and 50-64 years (69.1% and 78.1%, respectively).

CONCLUSIONS

YA with GC or CRC have distinctly worse clinical and histopathologic features compared with older patients and are disproportionately of Hispanic ethnicity. These results contribute to improving understanding of younger versus older GI cancer patients.

British Society of Gastroenterology guidelines on the diagnosis and management of patients at risk of gastric adenocarcinoma

Gastric adenocarcinoma carries a poor prognosis, in part due to the late stage of diagnosis. Risk factors include Helicobacter pylori infection, family history of gastric cancer-in particular, hereditary diffuse gastric cancer and pernicious anaemia. The stages in the progression to cancer include chronic gastritis, gastric atrophy (GA), gastric intestinal metaplasia (GIM) and dysplasia. The key to early detection of cancer and improved survival is to non-invasively identify those at risk before endoscopy. However, although biomarkers may help in the detection of patients with chronic atrophic gastritis, there is insufficient evidence to support their use for population screening. High-quality endoscopy with full mucosal visualisation is an important part of improving early detection. Image-enhanced endoscopy combined with biopsy sampling for histopathology is the best approach to detect and accurately risk-stratify GA and GIM. Biopsies following the Sydney protocol from the antrum, incisura, lesser and greater curvature allow both diagnostic confirmation and risk stratification for progression to cancer. Ideally biopsies should be directed to areas of GA or GIM visualised by high-quality endoscopy. There is insufficient evidence to support screening in a low-risk population (undergoing routine diagnostic oesophagogastroduodenoscopy) such as the UK, but endoscopic surveillance every 3 years should be offered to patients with extensive GA or GIM. Endoscopic mucosal resection or endoscopic submucosal dissection of visible gastric dysplasia and early cancer has been shown to be efficacious with a high success rate and low rate of recurrence, providing that specific quality criteria are met.

Early-onset gastric cancer is a distinct disease with worrisome trends and oncogenic features

BACKGROUND

Overall the incidence of gastric cancer is declining in the United States; however, the incidence of early-onset gastric cancer is increasing. We sought to elucidate clinical and genomic characteristics and risk factors for early-onset gastric cancer compared with late-onset gastric cancer.

METHODS

We utilized the Surveillance, Epidemiology, and End Results database (1973-2015), the Behavioral Risk Factor Surveillance Survey, and The Cancer Genome Atlas to characterize early-onset gastric cancer.

RESULTS

The incidence of early-onset gastric cancer increased during the study period and now comprises >30% of all gastric cancer in the United States. Early-onset gastric cancer was associated with higher grade (55.2 vs 46.9%), signet-ring cells (19.0 vs 10.4%), diffuse histology (25.7 vs 15.0%), and metastatic disease (49.5 vs 40.9%, all P < .01) compared with late-onset gastric cancer. Early-onset gastric cancer was more likely to be Epstein-Barr virus (7.7 vs 5.1%) or genomically stable (22.5 vs 8.1%) subtype, whereas late-onset gastric cancer was more likely to be microsatellite instability subtype (18.6 vs 5.6%; all P < .01). Risk factors for gastric cancer were less correlated with early-onset gastric cancer compared with late-onset gastric cancer.

CONCLUSION

The incidence of early-onset gastric cancer has been steadily increasing in the United States, comprising >30% of new gastric cancer cases today. Early-onset gastric cancer is genetically and clinically distinct from traditional gastric cancer. Additional investigations are warranted to better understand this alarming phenomenon.

Gastrointestinal cancer risk in patients with a family history of gastrointestinal cancer

Background/Aims

This study was performed to evaluate the relationship between family history of gastrointestinal (GI) cancers and incidence of any GI cancer in the Korean population.

Methods

Between January 2015 and July 2016, 711 GI cancer patients and 849 controls in 16 hospitals in Korea were enrolled. Personal medical histories, life styles, and family history of GI cancers were collected via questionnaire.

Results

There was a significant difference in the incidence of family history of GI cancer between GI cancer patients and controls (p=0.002). Patients with family history of GI cancer tended to be diagnosed as GI cancer at younger age than those without family history (p=0.016). The family members of GI cancer patients who were diagnosed before 50 years of age were more frequently diagnosed as GI cancer before the age of 50 years (p=0.017). After adjusting for major confounding factors, age (adjusted odds ratio [AOR] 1.065, 95% confidence interval [CI]; 1.053-1.076), male gender (AOR 2.270, 95% CI; 1.618-3.184), smoking (AOR 1.570, 95% CI; 1.130-2.182), and sibling's history of GI cancer (AOR 1.973, 95% CI; 1.246-3.126) remained independently associated with GI cancers.

Conclusions

GI cancer patients tended to have a first relative with a history of concordant GI cancer. Personal factors (old age and male) and lifestyle (smoking) contribute to the development of GI cancer, independently. Individuals with high risk for GI cancers may be advised to undergo screening at an earlier age.

The prognostic value of age in non-metastatic gastric cancer after gastrectomy: a retrospective study in the U.S. and China

Purpose: We explored the influence of age on clinicopathologic features and survival of patients with M0 gastric cancer (GC).

Methods: 16856 GC patients from Surveillance, Epidemiology and End Results (SEER) database and 1037 GC patients from Chinese multiple centers were enrolled in the U.S. and Chinese cohort, respectively. 50-year-old was treated as cutoff age. Propensity score method was used to carry out a 1:1 paired match.

Results: In the U.S. cohort, we found that younger patients presented poor tumor behavior. However, in spite of worse outcome in stage I~IV cohort, young group showed better 3-year survival in M0 patients, especially for those who underwent a total gastrectomy. In a matched analysis, a better prognosis was still observed in younger group. The prognostic value of age was also validated in M0 GC patients with gastrectomy in Chinese cohort.

Conclusions: In spite of the worse outcome in survival curve of stage I~IV GC cohort, young patients with gastrectomy presented favorable survival in M0 subgroup. It is also applicable in China. Early diagnosis and treatment should be taken seriously in young GC patients since they often possess poorer characteristics but benefited more from gastrectomy.

NDRG4 hypermethylation is a potential biomarker for diagnosis and prognosis of gastric cancer in Chinese population

In order to assess whether N-Myc downstream regulated gene 4 (NDRG4) methylation was associated with the diagnosis and prognosis of gastric cancer, we measured the methylation of NDRG4 promoter and gene body regions among 110 gastric cancer patients using quantitative methods (MethyLight and pyrosequencing). Both NDRG4 promoter and gene body methylation levels were increased in tumor tissues than paired adjacent normal tissues (P < 0.001). NDRG4 gene body methylation was found to be significantly associated with age and tumor differentiation. NDRG4 promoter hypermethylation was proved to be a predictor of poor overall survival. However, opposite result was observed among The Cancer Genome Atlas (TCGA) cohort. The findings from gastric cell lines and public databases have suggested that NDRG4 methylation level was inversely associated with NDRG4 transcription level. Subsequent luciferase reporter gene assay showed that promoter CpG island but not gene body CpG island was able to upregulate gene expression. Collectively, NDRG4 promoter hypermethylation contributed to the risk of gastric cancer and predicted a poor prognosis in Chinese gastric cancer patients. Moreover, the combined methylation levels of NDRG4 promoter and gene body served as diagnostic biomarkers in gastric cancer.

Gastric cancer and family history

Gastric cancer is associated with high morbidity and mortality rates worldwide. Identifying individuals at high risk is important for surveillance and prevention of gastric cancer. Having first-degree relatives diagnosed with gastric cancer is a strong and consistent risk factor for gastric cancer, but the pathogenic mechanisms behind this familial aggregation are unclear. Against this background, we reviewed the risk factors for gastric cancer in those with a first-degree relative with gastric cancer, and the possible causes for familial clustering of gastric cancer including bacterial factors, inherited genetic susceptibility, environmental factors or a combination thereof. Among individuals with a family history, current or past Helicobacter pylori infection, having two or more first-degree affected relatives or female gender was associated with an increased risk of developing gastric cancer. To date, no specific single nucleotide polymorphism has been shown to be associated with familial clustering of gastric cancer. H. pylori eradication is the most important strategy for preventing gastric cancer in first-degree relatives of gastric cancer patients, particularly those in their 20s and 30s. Early H. pylori eradication could prevent the progression to intestinal metaplasia and reduce the synergistic effect on gastric carcinogenesis in individuals with both H. pylori infection and a family history. Endoscopic surveillance is also expected to benefit individuals with a family history. Further large-scale, prospective studies are warranted to evaluate the cost-effectiveness and optimal time point for endoscopy in this population. Moreover, genome-wide association studies that incorporate environmental and dietary factors on a 'big data' basis will increase our understanding of the pathogenesis of gastric cancer.

Pepsinogens to Distinguish Patients With Gastric Intestinal Metaplasia and Helicobacter pylori Infection Among Populations at Risk for Gastric Cancer

OBJECTIVES

The objectives of this study were to investigate the serum pepsinogen test for the prediction of OLGIM (Operative Link on Gastric Intestinal Metaplasia Assessment) stages in first-degree relatives (FDR-GC) of patients with gastric cancer (GC) and autoimmune chronic atrophic gastritis (ACAG).

METHODS

In 67 consecutive patients with ACAG, 82 FDR-GC, and 53 controls (CTRL) without gastric disease (confirmed by biopsy), serum levels of pepsinogen 1 (PG1), pepsinogen 2 (PG2), G17, and the PG1/2 ratio were assessed by enzyme-linked immunosorbent assay kit. All ACAG patients had positive antiparietal cell antibody levels, estimated by indirect immunofluorescence. Biopsies taken in duplicate from the antrum, corpus, and fundus were stained with Giemsa for Helicobacter pylori detection. Endoscopic detection of metaplasia was confirmed by histological diagnosis. Histological classification of OLGIM stages was applied by using the criteria of severity and topography of intestinal metaplasia (IM).

RESULTS

The highest discrimination capacity for distinguishing ACAG from other groups of patients was the gastrin G17 test. The lowest mean for PG1 and PG2 serum levels was found in ACAG. In multivariate analysis by age, PG1 and PG1/PG2 were independent prognostic factors for metaplasia, and PG2 also for the presence of a histological H. pylori infection. The serum PG1 level was significantly lower in individuals with IM at OLGIM stage >2 than in those with IM at OLGIM stage <2, resulting in a useful method for the prediction of OLGIM stage. With the inclusion of patient age at diagnosis in the prediction of ≥2 vs. 0-1 OLGIM stages, the receiver operating characteristic (ROC) curve at 47.9 ng/ml PG1 level reached a significant area under the curve (AUC) value (0.978, P<0.001). We also observed a slight difference in PG2 serum levels between histological H. pylori-positive and H. pylori-negative subjects (ROC AUC: 0.599).

CONCLUSIONS

This study demonstrated an important increase in gastrin G17 serum level in autoimmune gastritis. PG1 serum level corrected by patient age can be used in the management of patients at risk for GC with a high predicted probability of having an OLGIM stage ≥2. Using a cutoff of 47.9 ng/ml, PG1 testing in FDR-GC and ACAG patients had a sensitivity of 95.83% and a specificity of 93.37. Although these results could be validated in a prospective study, the known importance of higher OLGIM stages in increasing the risk of GC development supports the rationale of proposing PG1 algorithm as a diagnostic tool for the selection of high-risk FDR-GC and ACAG patients at high-risk stages for subsequent detailed endoscopic examination to detect dysplasia and asymptomatic GC. In addition, serum PG1 and PG2 levels could stratify patients based on both H. pylori infection and OLGIM risk in consideration of the increased acknowledge regarding the role of H. pylori in the progression of gastritis to GC.

Molecular alterations in gastric cancer with special reference to the early-onset subtype

Currently, gastric cancer (GC) is one of the most frequently diagnosed neoplasms, with a global burden of 723000 deaths in 2012. It is the third leading cause of cancer-related death worldwide. There are numerous possible factors that stimulate the pro-carcinogenic activity of important genes. These factors include genetic susceptibility expressed in a single-nucleotide polymorphism, various acquired mutations (chromosomal instability, microsatellite instability, somatic gene mutations, epigenetic alterations) and environmental circumstances (e.g., Helicobcter pylori infection, EBV infection, diet, and smoking). Most of the aforementioned pathways overlap, and authors agree that a clear-cut pathway for GC may not exist. Thus, the categorization of carcinogenic events is complicated. Lately, it has been claimed that research on early-onset gastric carcinoma (EOGC) and hereditary GC may contribute towards unravelling some part of the mystery of the GC molecular pattern because young patients are less exposed to environmental carcinogens and because carcinogenesis in this setting may be more dependent on genetic factors. The comparison of various aspects that differ and coexist in EOGCs and conventional GCs might enable scientists to: distinguish which features in the pathway of gastric carcinogenesis are modifiable, discover specific GC markers and identify a specific target. This review provides a summary of the data published thus far concerning the molecular characteristics of GC and highlights the outstanding features of EOGC.